SI20572A - Scalping head for scalping cylindres, pipe-like cylinders ect. and scalping procedure - Google Patents

Abstract

To basically eliminate the error in roundness and to prevent the effect of spiral waves a scalping head is presented with radially located scalping knives, where at least three such knives are anticipated. By such a concept of the scalping head, the requirement of selfcentering of the set of scalping knives as well as circular geometry of the shell under unchanged depth of the chip can be met.

Description

ECOROLL AG Werkzeugtechnik Celle, Germany

Peeling head for extraction of cylinders, tubular cylinders, etc. and hatching process

The invention concerns a peeling head ¹ for extracting cylinders, tubular cylinders, and the like. and the extraction process using a peeling head, wherein the peeling head has radially non-peeling peeling knives arranged therein.

The processes and peeling heads of this type are known, for example, from the files DE 22 23 969 or DE 27 23 622; they are used for machining, especially the precise machining of cylindrical boreholes, such as those found in hydraulic cylinders and tubular cylinders, for example. Such boreholes are most economically accurately machined by peeling and smoothing. As a rule, the starting material is precisely drawn steel tubes or pre-drilled cast iron tubes with a small machining additive about 0.3 to 1 mm thick in diameter. These pipes have fabrication-related flatness errors that do not damage the purpose of the pipe and therefore do not need to be repaired by peeling.

In any case, the surface of the rotated wall must be peeled off throughout the surface and smoothed even with curved cylinders. The prerequisite for this is that, under the given conditions, the peeling knife of the macro-shaped tube follows from a nearly constant cutting depth. For this purpose, floating peeling knives, known for example from the already mentioned file DE 27 23 622 or DE 25 18 170, have acted. The peeling head is thus compared to the tool in two rav1. PEELING (German Schalefi) denotes machining by cutting off the surface of rolled and forged rods of circular cross-section on peeling machines for the production of light drawn steel. The nines are radially free-moving, and the peeling knife or knives are additionally radially flexible.

The known arrangement of peeling knives ensures self-centering of the knives with the passive cutting forces of both blades even when the peeling head does not rotate centrally due to external forces. The disadvantage of this arrangement, however, is that the peeling blades with two blades opposite each other do not produce a forced round hole. On the contrary, such blades perform radially oscillating motion while rotating the peeling head, forming a cross-section of a non-circular hole. This movement can be caused by a defect in roundness already in the tube itself or a slight disturbance in the balance of forces, such as variable passive cutting force at the generally desired fracture of the cut, and this movement can swing and continue over the entire machining length.

Typical for such borehole profiles is that the borehole - measured between two opposite points of contact - has a constant diameter, but that the inner mantle circle is smaller and the outer mantle circle larger than in the two-point process of the measured peel diameter. Polygons with 3, 5, 7 or more angles can be formed. This roundness error can lead to problems when assembling with piston and seals. Often, there is an error of roundness along the length of the pipe with an angular offset from one tool turn to another, thus obtaining a helical outline of the cylinder bore, which is generally regarded as a quality defect.

Tools without swinging blades are also known. These include drill bits such as those described, for example, in files DE 19 62 181 B, DE 16 52 790 A, DE 73 21 746 U and US 2,638,020. The cutter blades are all adjustable to the base body of the tool only in the same way and are not radially embedded. The drill bits are designed to produce boreholes with as little flatness error as possible. The further progress of the treatment therefore follows in the continuation of the current direction of the well. If the bore is curved, the bends are expected to completely eliminate this bend.

Tubular cylinders are made of precisely drawn steel tubes up to 10 m in length. Conditioned by machining procedures that were hitherto uncut, these pipes have a flatness error of up to 2 mm / m. At the same time, for cost reasons and to save material, work with machining accessories less than 1 mm in diameter. This means that there is not enough machining accessory available to make a straight hole from the curved one. This would require at least 4 mm in diameter of the machining additive at the above curvature. Tools that, like the drills described above, are designed to produce as straight holes as possible, in some places would pick up a lot of material, leaving other places intact. Therefore, the peeling head for the extraction of cylinders, tubular cylinders and the like therefore requires that the peeling tool in the machining follow the macro-shape of the borehole and thus summarize a given error in flatness. Retractors do not suffice this assumption.

Based on this, the invention is based on the task of creating a shell head and an excretion process that essentially eliminates the circular error and prevents the occurrence of helical waves.

The task is accomplished by a peeling head with radial-non-peeling peeling knives arranged in it, in which at least three peeling knives are provided. This design of the peeling head fulfills the requirement for both the self-centering of the peeling knife sentence and the circular shell geometry at a constant cutting depth.

Moreover, the great advantage of the invention is that, by providing at least three peeling blades, the peeling capacity can be increased in comparison with known peeling heads with only two peeling blades.

In a preferred embodiment of the invention, in which the peeling head has a central axis, it is contemplated that the adjacent peeling blades are arranged at similar angular intervals each time, in the direction of the middle axis of the peeling head. This ensures that in each rotation position the peeling head has the highest centering probability. The angular spacing would accordingly be 120 degrees for three knives, four for 90, five for 72, and six angular knives for each angle of 60 degrees. These angles can also vary slightly from sector to sector if necessary to avoid traces of interference.

In a further preferred embodiment of the invention, wherein the peeling head has a median axis and each peeling knife has at least one blade, it is provided that at least three blades of different peeling knives are arranged rotationally symmetrically with respect to the middle axis of the peeling head, meaning that they are on one blade of one peeling knife, the corresponding blades are provided on at least two other peeling blades, such that the corresponding points of the corresponding blades each determine a plane perpendicular to the middle axis of the peeling head. Since the middle axis of the peeling head is the main rotary axis in operation of the peeling head, this arrangement of the blades also has a positive effect on the centering of the peeling head in the hole being drawn.

The peeling capacity can be further increased by each peeling knife having at least two blades.

In a particularly advantageous embodiment of the invention, all the cutting blades are supported directly or indirectly by a joint, movably disposed conical or pyramidal body in the radiator head, and can be moved radially with respect to the shell head by means of this body. Depending on the design of the peeling head, the body may have the shape of a cone or truncated cone, as well as a pyramid or truncated pyramid, the term pyramid being not limited here, for example, to such regular polyhedra having a square base plane and for the mantle surfaces of the Four Congruent isosceles triangles, but the concept of the pyramid is understood in terms of geometric definition, and the pyramid may, in particular, have a basic face with as many sides as the peeling knives have provided.

Both the conical and the pyramid bodies make it possible, through a simple movement of the body, along the center axis of the separator head, to press radially out the radial blades, thereby adjusting in a particularly simple manner the appropriate diameter of the exfoliation.

In doing so, it turned out to be particularly expedient to place a conical or pyramid body in the shell head in a floating position. It is also preferred to provide means for variable fixing of the first relative position of the conical or pyramidal body relative to the peeling blades, whereby the conical or pyramidal body can be prestressed to the first relative position by means of suitable spring means. This first relative position is generally the working position of the peeling head, whereby the peeling knives are set to the desired peeling diameter.

In order that the peeling head can be easily and without causing scratches to be pulled out of the exfoliated body, the conical or pyramidal body may be so designed that it can be moved against the prestress by external, in particular hydraulic force, relative to the relative position the second relative position corresponds to the retracted position of the peeling blades, so that they no longer rest closely on the surface to be extracted and the peeling head is easily placed in the body being treated with ease move and position.

To ensure that the peeling blades are permanently or directly in contact with this conical or pyramidal body, and consequently, by changing the relative position of the conical or pyramidal body and the peeling blades, the desired setting of the peeling diameter may advantageously be provided by spring means that bias the peeling blades against conical or pyramidal body.

Preferably, these other spring means are arranged so that their direction of action does not extend through the center of the tool.

In order to prevent the blades from sticking, it is further suggested that the blades are guided in guides with a length-to-width ratio of more than 1.5, substantially greater than 2. The length-to-width ratio can be as high as 4 to 5 to obtain good guidance. In this case, length means the dimension of the guide in the radial direction, while width means the dimension of the guide in the axial direction.

The said problem is further solved by the process of extracting a cylinder, tubular cylinder or the like. with the aid of a radiator head of the introduced central axis with a few axes and a few peeling knives, using a head with at least three relative to the center axis of the peeling head of radially moving peeling knives.

In a preferred embodiment of the process, each blade having at least one blade has a knife, it is provided that the radial spacing of the blades is relative to the center axis of the peeling head - thereby adjusting the peeling diameter by means of a moving conical or pyramidal body in the peeling head. .

Further details and advantages of the invention are apparent from the following fully illustrative and non-limiting description of an embodiment of the exfoliation head of the invention in conjunction with the drawings in which

FIG. 1 peeling head according to the invention, along the central axis of the partially cut lateral lynx,

FIG. la detail in FIG. 1 shows peeling heads in knife area,

FIG. 2 is a partially cross-sectional view of the peeling head in FIG. 1,

FIG. 3 shows the operation of the centering forces in the operation of the peeling head, and

FIG. 4 shows an alternative embodiment of a peeling head along the mid-axis of a partially cut lateral lynx.

In the drawings of FIG. 1 to 3, a peeling head is represented as a whole, with reference number 9, and in which a total of three peeling blades 10 are radially displaced in a cylindrical housing 11.

In this case, each peeling knife 10 has two blades 3 and 3 '. The peeling blades 10 are guided in guides 10 ' with a high length / width ratio to prevent the peeling blades from sticking. In the embodiment shown, this guide is more than three times - exactly taken even more than five times - longer than wide. The guides 25 are each arranged between the peeling knives.

As in FIG. 2 is shown by example with only one knife, each peeling knife 10 is pressed radially inwards through the spring means 13 here, pressed radially inwards to adjust the peeling diameter of the sliding conical body, here in the form of a truncated cone 12. For this purpose, each peeling knife has 10 is a bearing 13 'for each pressure spring 13 at each point, again emphasizing that it is - different from that shown in FIG. 2 - by means of a pressure spring 13, as indicated by the arrows 13 in FIGS. 2 and 3, each peeling knife 10 is prestressed in the direction of the cone, but for the sake of clarity only one is indicated by a reference number. The truncated cone 12 is thereby floated in the shell head with the degrees of freedom 12 'and 12.

The compression springs 13 during peeling and in the tooled state, when the peeling blades are thus positioned in the radial direction, in the rearwardly drawn position towards the central axis, ensure the permanent contact of the blades 10 with the truncated cone 12.

A set of 15 screws and spacers is provided for fixing the first relative position of the truncated cone 12 and the peeling blades 10. The spring means, here in the form of a helical spring 14, prestress the truncated cone to this relative position corresponding to the working position in which the tool is ready for peeling.

When, in the direction of the arrow 16, for example, with the aid of a self-known hydraulics not shown hereafter, the truncated cone 12 can be moved along the common central axis 16 'of the peeling head 9 and the truncated cone 12 towards the prestressing of the spring 14, so that the peeling the blades 10 move radially inwards into the retracted position.

The truncated cone 12 is arranged in a floating position in the exfoliation head 9. As shown in FIG. 3, the straightness error for extending the prepared tubular cylinder for measure 19 changes the outline of the borehole 17 and the axis 17a of the borehole for measure 19 to position 18 or. 18a. This leads to an increase in the passive cutting forces of all in the sketch above the center of the working blades and at the same time to a decrease in the sketch of the lower forces. To this end, the truncated cone 12 responds with a radial reverse movement 20 by a measure 19. In this way, the whole blade statement is centered at the new center of the pipe while maintaining the circular shell geometry. In this way, the requirements for self-centering of the polishing knife sentence, circular geometry, and steadiness of the cutting depth are fulfilled. The compensatory displacement occurs by rotating the peeling tool or when the tool is stationary and the workpiece is rotated continuously and can be created with respect to the curvature of the tube in any direction.

Sketch of FIG. 4 shows an embodiment in which the force 16 acts on the wide side of the truncated cone 12 'and the helical spring 14' via a set 15 'of the screw and spacer to a smaller diameter of the truncated cone 12'. This arrangement also causes the blades 3 and the peeling blades 10 to move relative to the housing 11 '.

Within the scope of the invention, a number of variations and further variations are possible regarding, for example, the number and arrangement of peeling knives and blades. For example, it is possible to use, in particular, for peeling large diameters, peeling heads having more than the illustrative peeling knives shown. In any case, it is essential for the invention to provide more than two peeling blades, which significantly reduces the likelihood of involuntary radial oscillation.

Under the authority of:

Patent Office, d.o.o For her: Vinko Skubic

PmmiA BtSARNA, 0.0.0.

LJUBLJA ^ k ^ O ^ OVA 14

Claims (17)

A peeling head (9) for extracting cylinders, tubular cylinders and the like. with radially oscillatingly arranged peeling knives, characterized in that at least three peeling knives (10) are provided. A peeling head according to claim 1, wherein the peeling head has a central axis (16 '), characterized in that the adjacent peeling blades (10), when viewed in the direction of the middle axis (16') of the peeling head (9), are arranged each time at similar angular intervals. A peeling head according to claim 1 or 2, wherein the peeling head (9) has a central axis (16 ') and each peeling knife (10) has at least one blade (3, 3'), characterized in that there are at least three blades of different peeling blades arranged rotationally symmetrically with respect to the middle axis of the peeling head. Peeling head according to one of Claims 1 to 3, characterized in that all the peeling blades (10) are supported directly or indirectly by means of a jointly movable conical or pyramidal body (12) disposed in the peeling head and are movable therefrom. radially with respect to the peeling head. Peeling head according to claim 4, characterized in that a conical or pyramidal body (12) is incorporated in the peeling head (9) floating with two degrees of freedom (12 ', 12). Peeling head according to claim 4 or 5, characterized in that the means (15, 15 ') for variable fixing of the first relative position of the conical or pyramidal body (12) are relative to the peeling knives (10). Peeling head according to claim 6, characterized in that the first spring means (14) are provided for prestressing the conical or pyramidal body (12) in the first relative position. 8. A peeling head according to claim 7, characterized in that the conical or pyramidal body against the prestressing force is movable to another relative position by the use of an external, reasonably hydraulic force (16). Head peeling according to one of Claims 4 to 8, characterized in that other spring means (13) are provided for prestressing each peeling knife against the conical or pyramid body (12). Head peeling according to claim 9, characterized in that the other spring means (13) are arranged so that the direction of their action does not extend beyond the center of the peeling head. Peeling head according to one of the preceding claims, characterized in that the peeling knives (10) are guided in guides (10 ') whose length-to-width ratio is greater than 1.5, preferably greater than 2. 12. The process of extracting a cylinder, tubular cylinder or the like. with the aid of a ready-made body of the introduced peel head with a central axis and several peel blades, characterized in that a peel head with at least three relative to the middle axis of the peel head is radially moving peel blades. A method according to claim 12, wherein each knife has at least one blade, characterized in that the radial spacing of the blades with respect to the middle axis of the peeling head is adjusted by a moving conical or pyramidal body disposed in the peeling head. A method according to claim 13, characterized in that the peeling knives are prestressed against the conical or pyramidal body. Method according to claim 13 or 14, characterized in that the conical or pyramidal body is prestressed to the first relative position (working position) relative to the peeling knives. 16. A method according to claim 15, characterized in that for the purpose of moving the peeling head in the extracted body without treating the body, the conical or pyramidal body is pressed into the second relative position by introducing an external hydraulic force against the prestressing force when the radial displacement of the blades is with respect to the center axis of the shells, no heads smaller than in working position. 17. A body, in particular a cylinder and a tubular cylinder, with a cylindrical hollow space, characterized in that the hollow space has been treated using the polishing head according to one of claims 1 to 11 and / or by the method according to one of claims 12 to 16.